WSO2 has not a bin directory

I want to install WSO2 API manager. The install instructions talk about scripts in a /bin directory, but this directory doesn't exist. I have searched in several pages of documentation and I still didn't find out what I am doing wroing.

1. I download the release (I tried two, 2.6 and 4.1), in .zip and tar.gz format.
2. I uncompress the release file
3. I stop because there is no /bin directory inside the product-apim folder.

In fact, the /bin folder doesn't exist in the Github repository.

I see that all README keeps a initial step like this:

"Extract the wso2am-4.4.0.zip and go to the 'bin' directory" (https://github.com/wso2/product-apim#installation--running)

Well, where is the bin directory, or better, how can I get it?

The /bin directory is in the compiled product, which you can download from releases: https://github.com/wso2/product-apim/releases/tag/v4.3.0

In the source code, there is no /bin directory.